4-Nitrophenyl chloroformate → (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-((4-nitrophenoxy)-carbonyloxy)ethyl)pyridine 1-oxide

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Reaction Steps

(S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-hydroxyethyl)pyridine 1-oxide (1.5 g, 3.57 mmol), and DMAP (0.436 g, 3.57 mmol) were dissolved in DCM (50 ml), and 4-nitrophenyl carbonochloridate (0.863 g, 4.28 mmol) was added portion wise. The mixture was stirred at RT overnight. After 18 hours, the solvent was evaporated and the crude purified by silica gel flash chromatography (petroleum ether:EtOAc 3:7) affording (S)-3,5-dichloro-4-(2-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-((4-nitrophenoxy)carbonyloxy)-ethyl)pyridine 1-oxide (1.609 g, 2.75 mmol, 77% yield, MS/ESI+ 585 [MH]+).

Provenance & Evidence